Great events in Rome happen year-round… but some of my favorites happen to take place during the summer. So when it comes to summer in Rome, don’t worry: It’s not all about figuring out how to skip the lines and survive the heat. It’s also about some great summer events.

Best festivals for nightlife

My favorite: hands-down, the Lungo Il Tevere summer festival. This is when the Tiber River is lined with almost a mile of shops, stalls, bars, and restaurants. And it’s open until 2am. Come mid-June, every in-the-know Roman starts heading there to meet up with friends and have a drink, dance, or even just a stroll.

From now until April 17, Italy's state-run museums and sites are free. (Yay!) In Rome, that includes the Colosseum, Forum, Palazzo Massimo, Galleria Borghese (where you can find Raphael's beautiful "Entombment," above) and Baths of Caracalla… to name a few. Take advantage!

And let me tell you, grabbing night photos of those ruins while following a tour guide around was not the easiest….I’m glad my forgiving editor decided that at least one of the snaps was up to snuff. Here are a couple more..

Celebrate your Saturday night a little differently: From August 21, take a guided evening tour of the Colosseum (until October 2) or Baths of Caracalla (until October 23).

The option is especially exciting for the Colosseum, since the tours will include the subterranean area underneath the arena — a section that has never been opened to the public before. Under the stars (and, okay, installed lighting system), explore where the gladiators and animals would have waited for their turn in the arena. Bummer! I realized on a second reading that the website was a little unclear in saying that the subterranean area would be included: Did this mean you'd actually go into the subterranean area or that it would just be talked about? I gave them a follow-up call and it turns out the area is (still!) not open, so it'll be discussed only.

But I stand by the fact that it'll be a different, and uncrowded, way to see the Colosseum.

Tours of both the Colosseum and Baths of Caracalla, led by archaeologists, will be offered in English and Italian from 9pm to midnight each Saturday. The Colosseum costs €15 (including entrance), or €12 reduced; the Baths cost €10, or €8 reduced. To book, call +39 0639967700. For more information (in Italian), click here.

Addendum: For more information on how exactly to book (and do do so in advance), see my response to Jessica's comment, below.

Update, 9/13: Tickets for Colosseum entrances at night are now completely full. However, some times for the Baths of Caracalla remain free. English guided tours are at 10pm only.

In a word, the Baths of Caracalla are enormous. Towering 125 feet above you, they're higher than most apartment complexes in modern-day Rome; they accommodated up to 1,600 people at a time. Today, however, there's hardly anyone there.

The baths (or terme, in Italian) date back to the early 200s A.D., when they were planned by Emperor Septimus Severus and completed by his son Caracalla. They boasted a 183-by-79-foot frigidarium, tepidarium, 115-foot-wide caldarium, natatio (swimming pool) complete with bronze mirrors to reflect in the sunlight, and two palaestras, or gyms. And that's not to mention the complex's dozens of shops and two public libraries — one with texts in Latin, one in Greek.

Today, the baths' sheer size is enough to take your breath away. Experiencing that enormity and, with it, getting a sense of the monumental scale of ancient Rome's structures, is alone an excellent reason to visit. Unless you have a fascination with ancient baths, it's also pretty much the only reason: After centuries of looting and plundering, the baths are just a shell of what they would have been.

As with so many of Rome's other ancient sites, imagining the baths as they would have been requiressome imagination. (The History Channel has a short online video on the baths including a reconstruction, which helps; here is a scale drawing of the complex). If you go, remember that the entire bath complex would have been lavished with glass-paste mosaics (like that above), frescoes, and hundreds of sculptures.

Two of the sculptures, unearthed in the 16th century during excavations by Pope Paul III Farnese, give an idea of how monumental and lavish these decorations would have been: the Farnese Hercules and the Farnese Bull, an enormous sculpture group carved from one marble block that was probably originally a fountain (right), both now in Naples.

Visiting the baths costs € 6.00 for non-E.U. citizens; the ticket is also good for 7 days for Villa dei Quintili and the Mausoleo di Cecilia Metella. The complex is open daily from 9am to the evening (check the official Baths of Caracalla website for exact times, which vary by season), and to 2pm on Mondays. They're located just southeast of Circus Maximus, which is the closest metro stop. For a map, click here. To plot your route with public transport (official address is Viale delle Terme di Caracalla, 52), click here.